Have you purchased a home, but after the purchase, you discover the presence of mould affecting the use of your property?
These defects could be considered latent defects under the Civil Code of Quebec. Indeed, legal recourse could be taken to obtain a reduction in the sale price, the cancellation of the sale or damages, depending on the seriousness of the defects.
The legal warranty
Indeed, it is important to remember that in order to have the right to remedies and to the legal warranty provided for in article 1726 of the Civil Code of Québec, the defect must meet certain criteria. The defect must be:
- Hidden;
- Serious;
- Present at the time of sale;
- Unknown to the buyer at the time of the sale.
According to the same article of the Civil Code of Québec, in order for the defect to be qualified as a latent defect intended to enforce the warranty of legal quality, it must make the unfit property interfere with the use of the property for which it is intended or which so diminishes its usefulness that the buyer would not have purchased it, or would not have given such a high price, if he had known them.
As for mold, it is often considered a serious defect, since it can affect the health, structure of the building or the health of the occupants.
Indeed, as the case illustrates Jean-Marie v. Chénier , some types of mold can be very toxic. This is particularly the case for moulds belonging to the Aspergillus sp. and Penicillium sp. groups, which can be very harmful to the health of the inhabitants of the property due to their impact, particularly on the quality of the ambient air. Some of these types of molds also contain mycotoxins, which are toxic substances that pose a danger to human health.
Defect or normal wear and tear
It may happen that the court does not consider that mould is a latent defect, but rather that it results from the normal wear and tear of the property.
This is the case in the case Gagné v. Gauthier , where the buyer had purchased a house from the seller, suing him after the sale on the basis of latent defects. He had discovered mold behind the kitchen cabinets as well as on the floor beams. Due in particular to the evidence, the court concluded that these problems were common and then due to the age and normal wear and tear of the building, considering that it had been built in 1983.
Termination by the seller before the sale
When selling, the seller of the property has the obligation to report all defects in the house of which he is aware and not to make false declarations.
For example, in the case Brunet v. Plamondon , after purchase, buyers discovered significant water infiltration through the foundation that caused mold and fungal contamination. Before the sale, the seller had himself noticed a suspicious smell and observed the presence of mold by opening the basement walls. Rather than decontaminating, he closed the walls with improperly installed insulation, which encouraged condensation and made the situation worse. He then pulled the joints just before the pre-purchase inspection, preventing the inspector from using his thermal camera to detect moisture. The seller never informed the buyers of the actual condition of the premises or the fact that the walls had been contaminated. Considering that he had voluntarily concealed serious defects, the court ordered him to pay a reduction in the sale price as well as damages.
Notification of the defect by the buyer
When the conditions of the defect are met, it is your duty according to Article 1739 of the Civil Code to report the presence of the defect in writing to the seller within a period that is deemed reasonable. It is important not to proceed with repairs immediately, unless there is an emergency. In this way, the seller will be able to report the defect and make the necessary repairs, thus avoiding legal recourse.
If you do not give the buyer a useful period of time, and you proceed to repair the defects, the court may not award you the full amount you claim for the damages.
In the case of Boucher v. Bernard , home buyers discovered traces of mould and rot behind a toilet in the basement and at the base of the canopy shortly after the purchase. They immediately proceeded to demolish the basement and the glass roof, without allowing the saleswoman to see the problems. Since all the materials were discarded, there was limited evidence of the alleged defects. The court recognized the existence of certain latent defects, but ruled that the work carried out went beyond what was necessary and that the evidence was insufficient for some of the claims. It therefore granted only partial compensation.
It is therefore essential to allow the seller to identify the defects himself before undertaking any repairs.
Discovered a problem after buying your home? Our latent defect lawyers will help you assert your rights. Contact us now for an evaluation of your file.


